This book is about fish as food for humans. Humans have had exceptional evolutionary successes resulting in an ever-increasing population that has spread to all areas of our world and exploits a great deal of its resources. Some consequences of these successes are widescale environmental damage and massive loss of biodiversity. Now, the pollution caused by the technologies achieved by humans is damaging the air, the land and the sea and, by altering atmospheric chemistry, is driving climate change leading to global warming – melting ice caps and glaciers and causing floods, storms and fires. These, in turn, impact the capability of the planet to support the provision of food for humans.